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Across the WA electricity grid, demand management helps to support energy security and avoid power outages. 

Here’s your guide to peak demand, why it matters and what you could do to reduce the amount of electricity you require at your home during peak times.


What is peak demand?

Just as peak hour traffic occurs when there is a higher number of drivers using the roads, peak demand in the main WA electricity grid works in a similar way. 

Peak demand refers to when electricity consumption is the highest across an electrical grid.

Generally peak demand in WA happens in summer when extreme heat causes the demand for electricity to rise. This demand for electricity is usually highest between 5pm and 9pm on the hottest days. This is when many people arrive home from work or school and is primarily driven by people switching on their air conditioners, but usage of TVs, gaming consoles, lights and other appliances also increases the demand for electricity on the grid during these times.

Peak demand fact: On the hottest days in January, February and March each year, air conditioner use accounts for almost a third of the electricity consumed across the SWIS (the South West Interconnected System, the main WA electricity grid).

In winter, the SWIS experiences its highest demand on very cold weekday evenings when heating and appliances get switched on after many people have finished work. This demand is not as high as peak demand in summer, but still has an impact on the electrical grid.


Why does managing your electricity use during peak demand periods matter?

Making an effort to lower the amount of electricity you require at certain times can help to reduce peak demand. Here’s why this matters:

  • Across WA’s electricity industry, having enough electricity ready to meet a growing peak demand means additional electricity infrastructure such as generators and higher capacity powerlines need to be built. This infrastructure might only be used for a few hours, a few times a year when peak demand occurs – and ultimately the cost for this can translate into higher electricity prices. Without this additional infrastructure and electricity supply available, there could be power outages across the grid.
  • You might have a solar PV system – but unless you have a connected battery which stores any excess electricity generated, you will generally still be contributing to peak demand issues by drawing electricity from the grid when the sun goes down.

In short, peak demand impacts everyone across the SWIS. Demand management can help to balance the grid for the benefit of everyone in WA. 


How to take action to reduce peak demand at home

Reducing your demand for electricity at peak times could be easier than it sounds. Simply put, it involves reducing the use of your major appliances between 5pm and 9pm on the hottest weekdays of the year, or shifting their use to other times of the day.

Here are some ways you could help reduce peak demand in hot conditions.

Understand your demand

If you have a smart meter, you can check how you’re using electricity throughout the day through Synergy My Account. Once you know how much you’re using at different times, you could create a plan to shift some of your use or reduce your demand for electricity during peak times.

Cool your home slowly

When it’s hot, if you can set your air conditioning to achieve a comfortable temperature at home before the peak demand period sets in. Your system might have a timer or app which can help you do this. This way, you could be able to switch your air conditioner off during peak times because your home should already be cool.

For energy efficiency purposes, set your aircon to 24°C in summer. This should be lower than the outdoor temperature and will use less electricity than cranking your air conditioner by setting it to a lower temperature. 

Make the most of your fans

On warm nights, you could try to open your house up to let any breezes in and use a fan to move the cooler air around. This will generally use a lot less power than the average air conditioner – and it’s estimated that using a fan can make you feel up to 3°C cooler.

Plan your appliance use

On very hot days, you could help reduce peak demand by limiting your use of high energy-consuming appliances in the afternoon and evening.  Use only the appliances you really need and switch off others when they're not being used.

You could switch out your dinner prep using the oven or cooktop for your BBQ on hot evenings. This could help you to use less power-hungry appliances and generally won’t heat up your indoor spaces.

Use your pool, if you have one

Taking a quick dip could help you to cool down and can also help you to reduce your demand for electricity. If you can, try to avoid using your pool pump during peak times. You might be able to set this to run during the day before 5pm. Always follow your pool pump manufacturer’s recommendations.

Make the most of your solar power and/or time of use plan

If you have a solar PV system or you have made the switch to a time of use plan, hot days offer a good opportunity to make the most of your middle-of-the day electricity use. 

For example, you could run your dishwasher or washing machine at lunchtime instead of during peak times. This could either help you to make the most of your solar generation or shift your electricity use to outside peak times, if you have a time of use plan.

Small changes to your electricity use can help to keep the grid balanced. Discover more energy savings tips